Botulinum Neurotoxin A Intravesical Injections in Interstitial Cystitis/Bladder Painful Syndrome: A Systematic Review with Meta-Analysis

Bladder instillations vs onabotulinumtoxinA injection for interstitial cystitis/bladder pain syndrome: a randomized clinical trial

BACKGROUND

Interstitial cystitis (IC)/bladder pain syndrome (BPS) is an unpleasant sensation related to the bladder with lower urinary tract symptoms lasting more than 6 weeks, unrelated to an otherwise identifiable cause. The etiology is likely multifactorial including urothelial abnormalities, neurogenic pain upregulation, and potentially bladder and vaginal microbiome alterations. Despite treatment effectiveness of both bladder instillations and intradetrusor onabotulinumtoxinA injection for this condition, a head-to-head comparison has not been performed.

OBJECTIVE

To compare the efficacy of bladder instillations and intradetrusor onabotulinumtoxinA injection for treatment of IC/BPS.

STUDY DESIGN

Patients with O'Leary-Sant (OLS) questionnaire scores of ≥6, meeting clinical criteria for IC/BPS, and desiring procedural management were randomized to bladder instillations or intradetrusor onabotulinumtoxinA injection. The primary outcome was the difference in OLS scores at 2 months posttreatment between groups. Secondary outcomes included evaluation of sexual function, physical/mental health status, pain, patient satisfaction, treatment perception, retreatment, and adverse event rates.

RESULTS

Forty-seven patients were analyzed with 22 randomized to bladder instillations and 25 to onabotulinumtoxinA injection. There were no differences in demographic and clinical characteristics between groups. From baseline to 2 months posttreatment, there was a decrease in OLS subscales in all patients (Interstitial Cystitis Symptom Index [ICSI] -6.3 (confidence interval [CI] -8.54, -3.95), P<.0001; Interstitial Cystitis Problem Index [ICPI] -5.9 (CI -8.18, -3.57), P<.0001). At 2 months posttreatment, patients in the onabotulinumtoxinA group had significantly lower OLS scores compared to those in the bladder instillation group (ICSI 6.3±4.5 [onabotulinumtoxinA] vs 9.6±4.2 [instillation], P=.008; ICPI 5.9±5.1 [onabotulinumtoxinA] vs 8.3±4.0 [instillation], P=.048). The difference in OLS scores between groups did not persist at 6 to 9 months posttreatment. There were no statistically significant differences between baseline and posttreatment time points for the remaining questionnaires. Eight percent of patients who received onabotulinumtoxinA injection experienced urinary retention requiring self-catheterization. Patients who underwent onabotulinumtoxinA injection were significantly less likely to receive retreatment within 6 to 9 months compared to patients who received bladder instillations (relative risk 13.6; 95% CI, 1.92-96.6; P=.0002). There were no differences between groups regarding patient satisfaction, perception of treatment convenience, or willingness to undergo retreatment.

CONCLUSION

Both onabotulinumtoxinA injection and bladder instillations are safe, effective treatments for patients with IC/BPS, with significant clinical improvement demonstrated at 2 months posttreatment. Our findings suggest that intradetrusor onabotulinumtoxinA injection is a more effective procedural treatment for this condition than bladder instillation therapy and associated with decreased rates of retreatment.

Intravesical Botulinum Toxin Injection Plus Hydrodistention Is More Effective in Patients with Bladder Pain-Predominant Interstitial Cystitis/Bladder Pain Syndrome

Intravesical botulinum toxin A (BoNT-A) injections are included in the interstitial cystitis/bladder pain syndrome (IC/BPS) treatment guidelines. However, the IC phenotype suitable for treatment with BoNT-A has not been clarified. Therefore, we identified the factors influencing treatment outcomes for intravesical BoNT-A injections in patients with non-Hunner IC/BPS (NHIC). This retrospective study included patients with NHIC who underwent 100 U BoNT-A intravesical injections over the past two decades. Six months after treatment, treatment outcomes were assessed using the Global Response Assessment (GRA). Outcome endpoints included GRA, clinical symptoms, urodynamic parameters, urine biomarkers, and the identification of factors contributing to satisfactory treatment outcomes. The study included 220 patients with NHIC (42 men, 178 women). The satisfactory group (n = 96, 44%) had significantly higher pain severity scores and IC symptoms index, larger maximum bladder capacity (MBC), and lower 8-isoprostane levels at baseline. Logistic regression revealed that larger MBC (≥760 mL) and bladder pain predominance were associated with satisfactory outcomes after BoNT-A injection. Subjective parameters and pain severity scores improved significantly in patients with bladder pain-predominant IC/BPS after BoNT-A injection. Thus, NHIC patients with bladder or pelvic pain are more likely to experience satisfactory outcomes following intravesical BoNT-A injections.

Optimal endoscopic treatment and partial cystectomy with or without bladder augmentation for Hunner-type interstitial cystitis

Interstitial cystitis/bladder pain syndrome (IC/BPS) presents a significant challenge for urologists in terms of management, owing to its chronic nature and adverse impact on patient quality of life. Given the potential distinction between two disease entities within IC/BPS, namely Hunner-type IC and BPS without Hunner lesion, there is a need for an optimal therapeutic approach that focuses on the bladder lesions in Hunner-type IC. In cases where Hunner lesions are observed, complete transurethral ablation of these lesions should be prioritized as the initial intervention, as it has demonstrated effectiveness in symptom control. However, recurrence remains a limitation of this intervention. The techniques of resection and coagulation are equally effective in terms of symptom relief and recurrence prevention. Reconstructive surgery becomes necessary in cases of end-stage IC/BPS where various therapeutic approaches have failed. Patient selection is crucial in reconstructive surgery, particularly for patients with clear Hunner lesions and small bladder capacity who have not responded to previous treatments. Furthermore, it is vital to consider the patients' expectations and preferences adequately. Based on a comprehensive review of the literature and our own clinical experiences, subtotal cystectomy followed by bladder augmentation is considered a safe and effective surgical option. This stepwise and tailored therapeutic approach aims to optimize patients' quality of life by specifically targeting Hunner-type IC.

Botulinum Toxin Therapy for Bladder Pain Syndrome/Interstitial Cystitis

Purpose of Review

Bladder pain syndrome (BPS)/interstitial cystitis (IC) can also be classified as either non-ulcerative or ulcerative, corresponding to the characteristic cystoscopic findings under hydrodistention. Promising therapeutic effects, including decreased bladder pain, have been reported from recent clinical trials using botulinum toxin A (BoNTA) for the treatment of BPS/IC. This review summarizes the current state of the literature on the underlying mechanisms of BoNTA therapy in BPS/IC as well as new forms of its application.

Recent Findings

BoNTA has its effect in the central nervous system in the afferent nerves as well as in the bladder wall. Besides the well-known effects of BoNTA in the nervous system, pain control as well as reduction of urinary urgency in BPS patients could be achieved by mast cell stabilization effecting histamine release as well as modulation of TRPV and PGE2 pathways, among other systems. In addition, new forms of BoNTA administration have focused on intravesical instillation of the drug in order to circumvent bladder wall injections. Hyperthermia, intravesical hydrogel, and lysosomes have been studied as new ways of BoNTA application in BPS/IC patients. From the available studies, bladder instillation of BoNTA in combination with EMDA is the most promising and effective novel approach.

Summary

The most promising novel application methods for BoNTA in patient with BPS/IC are bladder instillations. Future research needs to point out if bladder instillations with BoNTA with some form of bladder absorption enhancement such as hyperthermia or EMDA would be able to replace BoNTA injections in patients with BPS/IC

Broaden Horizons: The Advancement of Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating disease that induces mental stress, lower urinary symptoms, and pelvic pain, therefore resulting in a decline in quality of life. The present diagnoses and treatments still lead to unsatisfactory outcomes, and novel diagnostic and therapeutic modalities are needed. Although our understanding of the etiology and pathophysiology of IC/BPS is growing, the altered permeability of the impaired urothelium, the sensitized nerves on the bladder wall, and the chronic or intermittent sensory pain with inaccurate location, as well as pathologic angiogenesis, fibrosis, and Hunner lesions, all act as barriers to better diagnoses and treatments. This study aimed to summarize the comprehensive information on IC/BPS research, thereby promoting the progress of IC/BPS in the aspects of diagnosis, treatment, and prognosis. According to diverse international guidelines, the etiology of IC/BPS is associated with multiple factors, while the presence of Hunner lesions could largely distinguish the pathology, diagnosis, and treatment of non-Hunner lesions in IC/BPS patients. On the basis of the diagnosis of exclusion, the diverse present diagnostic and therapeutic procedures are undergoing a transition from a single approach to multimodal strategies targeting different potential phenotypes recommended by different guidelines. Investigations into the mechanisms involved in urinary symptoms, pain sensation, and bladder fibrosis indicate the pathophysiology of IC/BPS for further potential strategies, both in diagnosis and treatment. An overview of IC/BPS in terms of epidemiology, etiology, pathology, diagnosis, treatment, and fundamental research is provided with the latest evidence. On the basis of shared decision-making, a multimodal strategy of diagnosis and treatment targeting potential phenotypes for individual patients with IC/BPS would be of great benefit for the entire process of management. The complexity and emerging evidence on IC/BPS elicit more relevant studies and research and could optimize the management of IC/BPS patients.

A bibliometric analysis of top-cited journal articles in interstitial cystitis and bladder pain syndrome

INTRODUCTION AND HYPOTHESIS

To identify and compare the top-cited articles from all indexed journals and urology-nephrology and obstetrics-gynecology journals in the Institute for Scientific Information Web of Science's Citation Index Expanded on interstitial cystitis and bladder pain syndrome (IC/BPS).

METHODS

Cross-sectional bibliometric analysis of top-cited articles in Web of Science^TM (WoS) from 1900-2022. The articles were retrieved by the MeSH terms from NCBI. The characteristics of top 100 cited articles from all indexed journals and specialized journals were evaluated.

RESULTS

A total of 5547 articles were collected from 1115 journals, in which 3225 articles were from 141 urological and gynecological specialized journals. The USA and the UK were the top two origins for articles on interstitial cystitis. The articles from non-specialized journals were more frequently cited than those from specialized journals (median [IQR], 221.5 [189.8-313.5] vs 131.0 [126.0-142.8], P < 0.0001). The citation number per year showed similar results (median [IQR], 239.9 [194.5-311.8] vs 132.0 [126.7-140.5], P < 0.0001). There were many more open-access articles in non-specialized than specialized journals (P = 0.0018).

CONCLUSIONS

The current study initially queried the articles published on WoS on IC/BPS by the number of citations to identify the differences between two journal categories. The characteristics and trends of research were analyzed by citations to provide insights into the current research status and future direction.

The clinical application of intravesical botulinum toxin A injection in patients with overactive bladder and interstitial cystitis

Botulinum toxin A (BoNT-A) has been widely used in several urological functional disorders including neurogenic detrusor overactivity (NDO), overactive bladder (OAB), lower urinary tract dysfunction, and interstitial cystitis/bladder pain syndrome (IC/BPS). Chronic inflammation is found in a large proportion of patients with OAB and IC/BPS. The chronic inflammation activates sensory afferents which resulting in central sensitization and bladder storage symptoms. Because BoNT-A can inhibit the sensory peptides released from the vesicles in sensory nerve terminals, the inflammation can be reduced and symptom subsided. Previous studies have demonstrated that the quality of life improved after BoNT-A injections, both in neurogenic and non-NDO. Although the use of BoNT-A in treatment of IC/BPS has not been approved by FDA, intravesical BoNT-A injection has been included in the AUA guideline as the fourth line therapy. Generally, intravesical injections of BoNT-A are well tolerated, though transient hematuria and urinary tract infection can occur after the procedure. In order to prevent these adverse events, experimental trials have been conducted to test if BoNT-A can be delivered into the bladder wall without intravesical injection under anesthesia such as using liposomes encapsulated BoNT-A or application of low energy shock wave on the bladder to facilitate BoNT-A penetrating across the urothelium and treat OAB or IC/BPS. This article reviews current clinical and basic researches of BoNT-A on OAB and IC/BPS.

An indirect comparison meta-analysis of noninvasive intravesical instillation and intravesical injection of botulinum toxin-A in bladder disorders

BACKGROUND

Botulinum toxin type A (BTX-A) intravesical instillation and BTX-A intravesical injection are both effective treatments or overactive bladder (OAB) and interstitial cystitis/bladder pain syndrome (IC/BPS), but direct comparative studies of the two treatments are lacking.

METHODS

We conducted a pairs-comparison meta-analysis and an adjusted indirect comparison meta-analysis extracting published data from randomized controlled trials in literature databases from the inception of each database to Aug. 31, 2021, evaluating efficacy and safety of BTX-A intravesical instillation and BTX-A intravesical injection. We also carried out a subgroup analysis.

RESULTS

We identified 24 trials in 21 studies were included in our study, of which 18 trials in 17 studies were BTX-A intravesical injections, 6 trials in 4 studies were BTX-A intravesical instillation. Compared with the normal saline injection, BTX-A intravesical injections for patients with OAB and IC/ BPS can obviously improve the symptoms of urinary frequency, urgency episode, UI and UUI, but BTX-A significantly increased the rate of urinary retention and urinary tract infection and increased PVR (p < 0.05). Adjusted indirect comparison meta-analysis showed that BTX-A intravesical injections was more effective than BTX-A intravesical instillation (p > 0.05). Surprisingly, BTX-A intravesical instillation had fewer side effects than BTX-A intravesical injections (p < 0.05).

CONCLUSIONS

Although BTX-A intravesical injections of OAB and IC/BPS has been significantly superior the BTX-A intravesical instillation, it has major side effects, but this needs to be confirmed by more large-scale, multicenter, direct comparison randomized controlled trials.

Comparative safety review of current pharmacological treatments for interstitial cystitis/ bladder pain syndrome

Introduction: Interstitial cystitis (IC)/bladder pain syndrome (BPS) is a frustrating disease of chronic bladder pain associated with lower urinary tract symptoms. Although there are many proposed treatment algorithms, the uncertainty as to their etiology has a negative impact on the therapeutic outcome. Oftentimes combination therapy of drugs with different mechanisms of action will be utilized to relieve the symptoms. With the various treatment options available to patients and providers, there is an ever-growing need to implement drug efficacy as well as safety to promote best practice in use of the approved drug.Areas covered: This review will focus on guideline-based pharmacotherapies as described by the AUA and EAU, specifically oral, and intravesical therapies with the most up-to-date published literature. Pharmacotherapies targeting bladder, and/or systemic factors in the overall treatment of IC/BPS are discussed with a particular focus on efficacy and drug safety evaluation.Expert opinion: IC/BPS is a syndrome that requires bladder targeting agents to restore the urothelium barrier function and inhibit bladder hypersensitivity as well as various drugs with anti-inflammatory effects, and immune modulation effects. Current pharmacotherapies for IC/BPS have various therapeutic effects and adverse effects depending on the dose and individual response.

Treatment of acute dysmenorrhoea and pelvic pain syndrome of uterine origin with myometrial botulinum toxin injections under hysteroscopy: A pilot study

BACKGROUND

Acute dysmenorrhoea in women which has been shown to be anatomically negative for endometriosis is a very common condition. It is frequently associated with Chronic Pelvic Pain (CPP) from uterine origin, including painful uterine contractions and deep dyspareunia. We call this association Painful Uterine Syndrome (PUS).

SEARCH STRATEGY

In these women in failure of the usual treatments, we proposed a new treatment, with Uterine Toxin Botulinic injections (BTX) under hysteroscopy, as a compassionate option, among women in severe pain and therapeutic failure. Indeed, increased uterine contractility has been confirmed using cine magnetic resonance imaging in patients with acute dysmenorrhea and PUS. These findings, associated with the hypothesis of a possible uterine sensitization on the same model as irritable bowel syndrome (IBS) or painful bladder syndrome (PBS), led to the application of botulinum toxin (BTX) injections under hysteroscopy of the uterine myometrium in this indication.

MATERIAL AND METHODS

In 2018, we conducted an open-label non comparative study, on 30 patients, with severe dysmenorrhea and PUS in therapeutic failure situation. All women had failure of usual treatments, with painkillers, anti-inflammatory drugs, contraceptive pill, menstrual suppressant therapy and a negative MRI and laparoscopy. The BTX units (200 IU of Incobotulinum-toxin A) were evenly distributed in the anterior and posterior myometrial wall under hysteroscopic control. Patients were reviewed between 8 and 12 weeks after BTX injections and then, at 6 months.

MAIN RESULTS

Median VAS scores were significantly improved at 8-12 weeks follow up for dysmenorrhoea, deep dyspareunia, and pelvic pain outside of menstruation. Quality of life scores all improved dramatically. No major side effect has been reported in this pilot study. At 6 months, 12 patients (40 %), were given new injections for pain reccurence. But 14 patients (47 %), were still improved and did not require repeat injection at that time. 4 patients, were improvement was not significant, did not ask for repat BTX injections. These patients were all positive for Pelvic Sensitization criteria.

CONCLUSIONS

Uterine BTX injection could be a very interesting therapeutic option in women with acute dysmenorrheoa and PUS in therapeutic failure. Only long-term randomised studies will be able to confirm that BTX injections are useful as a treatment for this condition. The randomised long-term study, Uteroxine, will shortly release its results.

Treatment of Interstitial Cystitis/Bladder Pain Syndrome: A Contemporary Review

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating condition affecting approximately 3% of the female population. IC/BPS is defined as an unpleasant sensation (pain, pressure, discomfort) perceived to be related to the urinary bladder, associated with lower urinary tract symptoms for more than six weeks duration, in the absence of infection or other identifiable cause. This condition is known to have a profound negative impact on quality of life. There are few well-studied treatment options and no cure for this condition, which is therefore challenging to treat. The purpose of this narrative review is to summarise the contemporary literature, including the Canadian Urological Association (CUA) and American Urological Association (AUA) guidelines, on various treatment options that exist for IC/BPS, including conservative therapies, oral therapies, intravesical therapies, and more invasive surgical options. Most importantly, this review highlights the need for an individualised, multimodal approach to the treatment of IC/BPS.

Effect of Botulinum Toxin A on Bladder Pain-Molecular Evidence and Animal Studies

Botulinum toxin A (BTX-A) is a powerful neurotoxin with long-lasting activity that blocks muscle contractions. In addition to effects on neuromuscular junctions, BTX-A also plays a role in sensory feedback loops, suggesting the potentiality for pain relief. Although the only approved indications for BTX-A in the bladder are neurogenic detrusor overactivity and refractory overactive bladder, BTX-A injections to treat bladder pain refractory to conventional therapies are also recommended. The mechanism of BTX-A activity in bladder pain is complex, with several hypotheses proposed in recent studies. Here we comprehensively reviewed properties of BTX-A in peripheral afferent and efferent nerves, the inhibition of nociceptive neurotransmitter release, the reduction of stretch-related visceral pain, and its anti-inflammatory effects on the bladder urothelium. Studies have also revealed possible effects of BTX-A in the human brain. However, further basic and clinical studies are warranted to provide solid evidence-based support in using BTX-A to treat bladder pain.